CN104487514B

CN104487514B - Thermoplastic polyurethane composition

Info

Publication number: CN104487514B
Application number: CN201380038561.4A
Authority: CN
Inventors: M·马尼丘; J·L·德格罗斯; T·科瓦尔斯基; M·E·贾斯蒂斯
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2012-06-12
Filing date: 2013-06-12
Publication date: 2020-04-28
Anticipated expiration: 2033-06-12
Also published as: ES2660761T3; EP2859044B1; CA2876356A1; US20150183989A1; WO2013188543A1; CN104487514A; CA2876356C; US9790365B2; EP2859044A1; WO2013188543A4; PL2859044T3

Abstract

A thermoplastic polyurethane composition includes a Thermoplastic Polyurethane (TPU) and polyoxymethylene. The thermoplastic polyurethane composition comprises 50 to 95 parts by weight of TPU and 5 to 50 parts by weight of polyoxymethylene per 100 parts by weight of the thermoplastic polyurethane composition. The thermoplastic polyurethane composition has an Izod notched impact strength at-40 ℃ of greater than 0.5fflb/in as measured by ASTM D25610, method A and an elastic modulus at 130 ℃ of greater than 700psi as measured by ASTM D412. A fluid transfer tube is formed from the thermoplastic polyurethane composition.

Description

Thermoplastic polyurethane composition

Cross reference to related applications

The benefit and priority of U.S. provisional patent application No.61/658,657, filed on 12.6.2012, the entire disclosure of which is incorporated herein by reference.

Technical Field

The present invention generally relates to thermoplastic polyurethane compositions, methods of making the thermoplastic polyurethane compositions, and fluid transfer tubes formed from the thermoplastic polyurethane compositions. The invention more particularly relates to thermoplastic polyurethane compositions that can be used in place of polyamides.

Background

Thermoplastic polyurethane compositions (TPU compositions) are known in the art and may be used in a variety of products. The TPU compositions generally include a Thermoplastic Polyurethane (TPU), fillers, and additives. TPUs are generally multiblock copolymers containing hard and soft segments which can be prepared by polyaddition of isocyanates with linear polymer diols and low molecular weight diols as chain extenders. Generally, the soft segment constitutes the elastomeric matrix that imparts elastomeric properties to the TPU. The hard segments generally serve as multifunctional tie points, which serve both as physical cross-linking points and as reinforcing fillers. TPUs are known in the art for their toughness, low temperature flexibility, strength, abrasion resistance, transparency, and chemical resistance. By adjusting the nature and amount of the isocyanate, linear polymer diol and/or low molecular weight diol, these physical properties can be tailored to suit different end uses.

While TPUs typically have many desirable physical properties, many TPUs also have physical properties that make them unsuitable for certain uses. For example, TPUs may exhibit insufficient physical properties, such as low softening point, tensile strength, elongation at break, tear strength, and modulus, especially at higher temperatures. For this reason, articles formed from TPU compositions may have insufficient wear resistance, i.e., the ability to withstand mechanical effects such as friction, scraping, or erosion. Some articles formed from TPU compositions may simply not be durable enough at higher temperatures. For example, TPU compositions have not traditionally been used in various hose applications that are subjected to elevated environmental and fluid temperatures. Many of these hose applications currently utilize other polymer compositions, including polymers that generally have adequate physical properties at higher temperatures, such as polyamides, e.g., nylon 11 and nylon 12.

When TPU compositions are used, polymers other than TPU are sometimes included to improve physical properties. For example, it is known in the art to blend TPU and Polyoxymethylene (POM) to improve impact resistance. In this case, the TPU is typically blended in an amount of 40 wt% or less and the POM is typically blended in an amount of 60 wt% or more, based on the total weight of the TPU and POM. In addition, in many cases, it is also necessary to add a second polymer or filler to the blend of TPU and POM to obtain the desired impact resistance.

Disclosure of Invention

Summary of the invention and advantages

A thermoplastic polyurethane composition (TPU composition) comprising a Thermoplastic Polyurethane (TPU) and a polyoxymethylene is disclosed. The TPU composition comprises 50 to 95 parts by weight TPU and 5 to 50 parts by weight polyoxymethylene per 100 parts by weight TPU composition. The TPU composition has an Izod notched impact strength greater than 0.5 ft.lb/in at-40 ℃ as measured by ASTM D25610, method A and an elastic modulus greater than 700psi at 130 ℃ as measured by ASTM D412. Also disclosed are fluid transfer tubes comprising the TPU compositions.

The TPU compositions of the present disclosure exhibit excellent physical properties over a wide temperature range, such as relatively high softening point, tensile strength, elongation at break, tear strength, elastic modulus, and flexural modulus. More specifically, the TPU composition retains excellent low temperature properties such as notched izod impact strength at-40 ℃, but has excellent room temperature and elevated temperature properties such as tensile strength, elongation at break, tear strength, elastic modulus, and flexural modulus at 23 ℃ and 130 ℃. These physical properties allow the TPU compositions to be used in place of other polymers, such as polyamides, to form articles such as fluid (e.g., liquid, gas, plasma, etc.) transmission tubes and cable jackets. Further, it is believed that the polyurethane compositions of the present disclosure may be useful in applications where other polymers, such as polyamides, are not suitable, such as sub-zero applications, including food packaging films, ski boots, and the like.

Detailed Description

The present disclosure provides thermoplastic polyurethane compositions (TPU compositions), methods of forming fluid transfer tubes, and fluid transfer tubes formed from the thermoplastic compositions. The TPU composition includes a Thermoplastic Polyurethane (TPU) and an acetal polymer, such as polyoxymethylene. The TPU composition is generally free of foam-specific cells and there is generally no cell formation in the formation that results from the action of the blowing agent.

While a wide variety of TPUs can be formed by varying the structure and/or molecular weight of the reactants used to form the TPU, the TPU of this disclosure is designed to be used in TPU compositions with polyoxymethylene. The TPU is typically selected from polyester based TPU, polyether based TPU, and combinations thereof. For purposes of this disclosure, a "polyester-based" TPU is a TPU that includes at least two ester groups present therein and/or is formed from reactants that include a polyester bond. Likewise, also for purposes of this application, a "polyether-based" TPU is a TPU that includes at least two ether groups present therein and/or is formed from reactants that include polyether linkages. It will be appreciated that for both polyester-based and polyether-based TPUs, reactants in which polyester or polyether groups are not included may be used to form the TPU. Further, it should also be recognized that TPUs suitable for use in the present disclosure are not limited to polyester-based or polyether-based TPUs, and that other TPUs not including ether or ester groups present therein may also be suitable.

The TPU generally comprises the reaction product of a polyol and an isocyanate. In one embodiment, the TPU is a polyester based TPU and includes the reaction product of a polyester polyol and an isocyanate. Suitable polyester polyols can result from the reaction of a dicarboxylic acid and a diol having at least one primary hydroxyl group. Suitable dicarboxylic acids may be selected from, but are not limited to, adipic acid, methyladipic acid, succinic acid, suberic acid, sebacic acid, oxalic acid, glutaric acid, pimelic acid, azelaic acid, phthalic acid, terephthalic acid, isophthalic acid, and combinations thereof. Suitable diols for use in making the polyester polyols can be selected from, but are not limited to, ethylene glycol, butylene glycol, hexylene glycol, bis (hydroxymethylcyclohexane), 1, 4-butanediol, diethylene glycol, 2-dimethylpropanediol, 1, 3-propanediol, and combinations thereof.

In another embodiment, the TPU is a polyether based TPU and includes the reaction product of a polyether polyol and an isocyanate. Suitable polyether polyols may be selected from, but are not limited to, polybutylene glycol, polyethylene glycol, polypropylene glycol, and combinations thereof.

In yet another alternative embodiment, the TPU may comprise the reaction product of a chain extender and an isocyanate in the absence of a polyester polyol and/or polyether polyol, respectively, suitable chain extenders may be selected from, but are not limited to, glycols including ethylene glycol, propylene glycol, butylene glycol, 1, 4-butanediol, butylene glycol, butynediol, xylene glycol, pentylene glycol, 1, 4-phenylene-bis- β -hydroxyethyl ether, 1, 3-phenylene-bis- β -hydroxyethyl ether, bis- (hydroxy-methyl-cyclohexane), hexylene glycol, and thiodiglycol, diamines including ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, phenyl diamine, toluene diamine, phenyl dimethylamine, 3 '-dichlorobenzidine, and 3,3' -dinitrobenzidine, alkanolamines including ethanolamine, aminopropyl alcohol, 2-dimethyl amine, 3-aminocyclohexyl alcohol, and p-propanol, and combinations of any of the foregoing chain extenders.

Typically, the polyol used to form the TPU has a weight average molecular weight of from 600 to 2,500 g/mol. It will be appreciated that when a plurality of polyols are used to form the TPU, each of the polyols typically has a weight average molecular weight within the ranges described above. However, the polyol used to form the TPU is not limited to this molecular weight range.

The isocyanate used to form the TPU may be a polyisocyanate having two or more functional groups, for example two or more NCO functional groups. The isocyanate may include, but is not limited to, monoisocyanates, diisocyanates, polyisocyanates, biurets formed from isocyanates and polyisocyanates, isocyanurates formed from isocyanates and polyisocyanates, and combinations thereof. In one embodiment, the isocyanate comprises an n-functional isocyanate. In this embodiment, n is a number typically from 2 to 5, more typically from 2 to 4, most typically from 2 to 3. It is to be understood that n may be an integer or may have an intermediate value of 2 to 5. The isocyanate may comprise an isocyanate selected from the group consisting of aromatic isocyanates, aliphatic isocyanates, and combinations thereof. In another embodiment, the isocyanate includes aliphatic isocyanates such as hexamethylene diisocyanate, H12MDI, and combinations thereof. If the isocyanate comprises an aliphatic isocyanate, the isocyanate may also comprise a modified polyvalent aliphatic isocyanate, i.e. a product obtained by chemical reaction of an aliphatic diisocyanate and/or an aliphatic polyisocyanate. Examples include, but are not limited to, urea, biuret, allophanate, carbodiimide, uretonimine, isocyanurate, urethane groups, dimers, trimers, and combinations thereof. The isocyanate may also include, but is not limited to, modified diisocyanates used independently or in reaction products with polyoxyalkylene glycols, diethylene glycols, dipropylene glycols, polyoxyethylene glycols, polyoxypropylene polyoxyethylene glycols, polyesterols, polycaprolactones, and combinations thereof.

Alternatively, the isocyanate may comprise an aromatic isocyanate. If the isocyanate comprises an aromatic isocyanate, the aromatic isocyanate may correspond to the formula R' (NCO)_zWherein R 'is aromatic and z is an integer corresponding to the valence of R'. Typically, z is at least 2. Suitable examples of aromatic isocyanates include, but are not limited to, tetramethylxylylene diisocyanate (TMXDI), 1, 4-phenylene diisocyanate, 1, 3-diisocyanato-o-xylene, 1, 3-diisocyanato-p-xylene, 1, 3-diisocyanato-m-xylene, 2, 4-diisocyanato-1-chlorobenzene, 2, 4-diisocyanato-1-nitrobenzene, 2, 5-diisocyanato-1-nitrobenzene, m-phenylene diisocyanate, p-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, mixtures of 2, 4-and 2, 6-toluene diisocyanate, 1, 5-naphthalene diisocyanate, toluene diisocyanate, mixtures thereof, and mixtures thereof, 1-methoxy-2, 4-phenylene diisocyanate, 4' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate, 4' -biphenyl diisocyanate, 3' -dimethyl-4, 4' -diphenylmethane diisocyanate, 3' -dimethyldiphenylmethane-4, 4' -diisocyanate, triisocyanates, such as 4,4' -triphenylmethane triisocyanate, polymethylene polyphenylene polyisocyanate and 2,4, 6-toluene triisocyanate, tetraisocyanates, such as 4,4' -dimethyl-2, 2' -5,5' -diphenylmethane tetraisocyanate, toluene diisocyanate, 2' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate, mixtures thereof, and mixtures thereof, 2,4 '-diphenylmethane diisocyanate, 4' -diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanates, their corresponding isomer mixtures, and combinations thereof. Alternatively, the aromatic isocyanate may include m-TMXDI andtriisocyanate product of 1,1, 1-trimethylolpropane, reaction product of toluene diisocyanate and 1,1, 1-trimethylolpropane, and combinations thereof. In one embodiment, the isocyanate comprises a diisocyanate selected from the group consisting of methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, H12MDI, and combinations thereof.

In one embodiment, the isocyanate has an NCO content of up to 85.7 weight percent. The isocyanate may also be reacted with the polyol and/or chain extender in any amount as determined by one skilled in the art. Typically, the isocyanate and polyol and/or chain extender are reacted at an isocyanate index of from 90 to 115, more typically from 95 to 105, most typically from 105 to 110.

Reference is now made to TPUs, which generally have: a weight average molecular weight of greater than 50,000, more typically 50,000 to 400,000, most typically 75,000 to 200,000 g/mol; a softening point of greater than 150, more typically greater than 160 ℃, as measured by ASTM D1525-09; a melting point of 210 to 225 ℃; a shore D hardness of 51 to 75pts as measured by ASTM D2240; and 1.1 to 1.3, more typically 1.13 to 1.23, most typically 1.16 to 1.20g/cm³Specific gravity of (a). In one embodiment, the TPU has a shore D hardness of 51 to 55 and a specific gravity of 1.15 to 1.17. In another embodiment, the TPU has a shore D hardness of 71 to 75 and a specific gravity of 1.18 to 1.20.

Furthermore, the TPU generally has: a tensile strength at 23 ℃ of 2,000 to 10,000, more typically 3,000 to 9,000psi as measured by ASTM D412; taber abrasion resistance of 50 to 100, more typically 65 to 85mg when tested according to ASTM D1044; and a tear strength at 23 ℃ of greater than 800, more typically greater than 950pli, as measured by ASTM D624, die c (die c). Specific examples of suitable TPUs include, but are not limited to, those available from BASF Corporation

TPU。

Of course, it is contemplated that the TPU composition may include one or more TPUs. When more than one TPU is included in the TPU composition, the more than one TPU meets the description of the TPU given above, and the additional TPU is not limited to any particular TPU, but generally includes polyether-based TPU and/or polyester-based TPU.

The TPU is typically present in the TPU composition in an amount of from 50 to 95 parts by weight, more typically from 51 to 95 parts by weight, even more typically from 55 to 90 parts by weight, even more typically from 60 to 90 parts by weight, and most typically from 65 to 85 parts by weight per 100 parts by weight of the TPU composition. When the TPU composition includes more than one TPU, the total amount of TPU present in the TPU composition is within the above ranges.

In one embodiment, a single polyether based TPU is present in the TPU composition in an amount of 70 to 85 parts by weight per 100 parts by weight of the TPU composition. In this embodiment, the polyether based TPU has a shore D hardness of 51 to 55 and a specific gravity of 1.15 to 1.17.

In another embodiment, a single polyether based TPU is present in the TPU composition in an amount of 70 to 85 parts by weight per 100 parts by weight of the TPU composition. In this embodiment, the TPU has a shore D hardness of 71 to 75 and a specific gravity of 1.18 to 1.20.

In addition to the TPU, the TPU composition includes an acetal polymer. As noted above and not to be bound by any particular theory, it is believed that the acetal polymer provides improved physical properties at higher temperatures to the TPU composition. The acetal polymer may be further defined as a homopolymer, a copolymer, or a mixture of a homopolymer and a copolymer. Typically, the acetal polymer is further defined as polyoxymethylene. Polyoxymethylene can be further defined as a homopolymer, a copolymer, or a mixture of a homopolymer and a copolymer. Polyoxymethylene can be further defined as polyoxymethylene homopolymer (- (-O-CH)₂-)_n-) where n can be any number greater than 1. As is known in the art, homopolymers of polyoxymethylene are generally synthesized by polymerizing anhydrous formaldehyde by anionic catalysis and then stabilized by reaction with acetic anhydride. As another example, the polyoxymethylene may be a polyoxymethylene copolymer. Also as known in the art, the copolymerization of polyoxymethylene can be synthesized by converting formaldehyde to trioxane via acid catalysis, and then reacting trioxane with dioxolane or ethylene oxide using an acid catalyst to form a copolymerA compound (I) is provided.

Typically, the polyoxymethylene has: a weight average molecular weight of greater than 50,000, more typically from 50,000 to 250,000, most typically from 100,000 to 200,000 g/mol; a melting point greater than 160, more typically greater than 165 ℃; a tensile strength (yield) at 23 ℃ of 8,000 to 11,000, more typically 8,500 to 10,500, most typically 9,000 to 10,000psi as measured by ASTM D638; an elongation (yield) at 23 ℃ of 2 to 20, more typically 5 to 15, most typically 8 to 10%, as measured by ASTM D638; a flexural modulus at 23 ℃ as measured by ASTM D790 of 300,000 to 400,000, more typically 325,000 to 75,000, and most typically 355,000 to 365,000 psi; notched Izod impact strength at 23 ℃ of 1 to 2, more typically 1.2 to 1.4 ft-lb/in as measured by ASTM D256; and an Izod notched impact strength at-40 ℃ of from 1 to 2, more typically from 1.0 to 1.3 ft-lb/in as measured by ASTM D256. In one embodiment, the polyoxymethylene has a melting point of about 166 ℃. In another embodiment, the polyoxymethylene has a tensile strength of 9,000 to 10,000psi at 23 ℃ as measured by ASTM D638. Examples of suitable polyoxymethylenes that can be used include, but are not limited to, those available from BASF corporation

Polyoxymethylene.

The polyoxymethylene is typically present in the TPU composition in an amount of from 5 to 50, even more typically from 5 to 49, even more typically from 5 to 45, even more typically from 5 to 40, even more typically from 10 to 35, and most typically from 13 to 32 parts by weight per 100 parts by weight of the TPU composition. Further, it is recognized that more than one polyoxymethylene may be included in the TPU composition, in which case the total amount of all polyoxymethylenes present in the TPU composition is within the above ranges. Generally, if more than 50 parts by weight of polyoxymethylene is present in the TPU composition, the low temperature properties of the TPU composition (i.e., Izod at-40 ℃) will begin to decrease. For example, a test specimen formed from a TPU composition containing more than 50 parts by weight of polyoxymethylene may break when tested for notched Izod impact strength at-40 ℃ according to ASTM D256-10 (method A).

In addition to the TPU and acetal polymer, the TPU composition may also include a crosslinking agent that reacts with the TPU to form crosslinking points, i.e., to form a crosslinked TPU. The crosslinking agent reacts with the TPU to produce a reinforced polymer network. The crosslinking agent comprises a thermoplastic polyurethane carrier, other than a TPU, and an isocyanate component. The crosslinking agent generally includes less than 60 parts by weight of the thermoplastic polyurethane carrier and generally less than 48 parts by weight of the isocyanate component, based on 100 parts by weight of the crosslinking agent.

The isocyanate component of the crosslinker includes at least one isocyanate. Isocyanates suitable for use in the isocyanate component include, but are not limited to, aliphatic and aromatic isocyanates. In various embodiments, the isocyanate is selected from the group consisting of diphenylmethane diisocyanate (MDI), polymeric diphenylmethane diisocyanate (pMDI), Toluene Diisocyanate (TDI), Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), and combinations thereof.

The isocyanate component of the crosslinker may include an isocyanate prepolymer. The isocyanate prepolymer is typically the reaction product of an isocyanate and a polyol and/or polyamine. The isocyanate used in the prepolymer may be any isocyanate as described above. The polyol used to form the prepolymer is typically selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, biopolyols, and combinations thereof. The polyamines used to form the prepolymer are typically selected from the group consisting of ethylenediamine, tolylenediamine, diaminodiphenylmethane and polymethylene polyphenylene polyamines, aminoalcohols, and combinations thereof. Examples of suitable aminoalcohols include ethanolamine, diethanolamine, triethanolamine, and combinations thereof.

In one embodiment, the crosslinker comprises a thermoplastic polyurethane carrier and the isocyanate component comprises an isocyanate prepolymer, diphenylmethane-4, 4' -diisocyanate (MDI) and a mixed isomer of MDI. In this embodiment, the crosslinking agent comprises less than 60 parts by weight of the thermoplastic polyurethane carrier, less than 25 parts by weight of the isocyanate prepolymer, 20 parts by weight of MDI and less than 3 parts by weight of the mixed isomer of MDI, based on 100 parts by weight of the crosslinking agent.

When the TPU includes a crosslinking agent, crosslinking occursThe agent is typically present in the TPU composition in an amount of from 1 to 15, more typically from 3 to 8, parts by weight per 100 parts by weight of the TPU composition. Examples of useful crosslinking agents include, but are not limited to, those available from BASF corporation

And (5) producing the product. The crosslinking agent contains isocyanate groups that react with the TPU to produce a reinforcing network.

In addition to the TPU and acetal polymer, the TPU composition can also include a compatibilizer that helps compatibilize the TPU and acetal polymer, thereby promoting the homogeneity of the TPU composition, which in turn optimizes the physical properties of the TPU composition. Typically, the compatibilizer is an anhydride-functional compatibilizer. More typically, the compatibilizer is a maleic anhydride-functional polyethylene or polypropylene-based compatibilizer. The maleic anhydride functionality improves the interfacial interaction between the TPU and acetal polymer, e.g., polyoxymethylene, which generally results in a more uniform blend of TPU and polyoxymethylene. In one embodiment, the compatibilizer is a Low Density Polyethylene (LDPE) -based maleic anhydride grafted compatibilizer.

In addition to the TPU and acetal polymer, the TPU composition may include one or more additives selected from the group consisting of antifoams, processing additives, plasticizers, chain terminators, surface-active agents, accelerators, flame retardants, antioxidants, water scavengers, fumed silica, dyes, ultraviolet light stabilizers, fillers, thixotropic agents, transition metals, catalysts, blowing agents, surfactants, crosslinking agents, inert diluents, and combinations thereof. Some particularly suitable additives include, but are not limited to, carbodiimides to reduce hydrolysis, hindered phenol and hindered amine light stabilizers to reduce oxidation and yellowing, benzotriazoles to improve ultraviolet light stabilization, glass fillers, and sulfonates to improve the antistatic properties of the TPU composition. The one or more additives may be included in any amount desired by one skilled in the art.

As used herein, "consisting essentially of …" is intended to exclude any ingredient or combination of ingredients and any amount of any ingredient or combination of ingredients, such as fillers, plasticizers, and polyamides, that would alter the basic and novel characteristics of the TPU composition. In one embodiment, the TPU composition consists essentially of TPU and polyoxymethylene. In another embodiment, the TPU composition consists essentially of a TPU, a polyoxymethylene, and a crosslinking agent. In yet another embodiment, the TPU composition consists essentially of a TPU, a polyoxymethylene, and a compatibilizer. In yet another embodiment, the TPU composition consists essentially of TPU, polyoxymethylene, a crosslinking agent, and a compatibilizer.

The TPU composition may be substantially free of other polymers known in the art, including polyamides, fillers known in the art, including reinforcing fillers, and plasticizers known in the art. The term "substantially free" as used immediately above refers to an amount of less than 0.1, more typically less than 0.01, and most typically less than 0.001 parts by weight per 100 parts by weight of the polyamide composition.

Typically, the TPU composition has a weight percent of from 1.05 to 1.35, more typically from 1.11 to 1.25, most typically from 1.15 to 1.21g/cm as measured by ASTM D792³Specific gravity of (a). In one embodiment, the TPU composition has a viscosity of about 1.15g/cm³The density of (c). The TPU composition also typically has a shore D hardness as measured by ASTM D2240 of 50 to 100, more typically 55 to 90, most typically 60 to 80 pts. In another embodiment, the TPU composition has a shore D hardness of 62 to 67. In yet another embodiment, the TPU composition has a shore D hardness of 72 to 80.

Further, the TPU composition typically has a viscosity of 5 to 50, more typically 10 to 40, most typically 15 to 35mm as measured by DIN 53516³DIN abrasion loss of (1). The TPU composition also typically has a tensile strength at 23 ℃ of greater than 3,500, more typically 5,000 to 9,000, and most typically 5,500 to 8,000psi as measured by ASTM D412. In an additional embodiment, the TPU composition has a tensile strength of about 7,500psi at 23 ℃. Further, the TPU composition typically has a tensile strength at 130 ℃ of greater than 175, more typically from 150 to 600, and most typically from 200 to 550, as measured by ASTM D412. In another additional embodiment, the TPU composition has a tensile strength of about 200psi at 130 ℃. The TPU composition generally has a temperature at 23 ℃ as measured by ASTM D412 of greater than 140, moreTypically 150 to 500, most typically 170 to 550% elongation at break. In a further embodiment, the TPU composition has an elongation at break of about 400%. The TPU composition typically has a tear strength at 23 ℃ of greater than 900, more typically greater than 1,200, and most typically greater than 1,500pli as measured by ASTM D624, die C. The TPU composition typically has an elastic modulus at 23 ℃ of 20,000 to 75,000, more typically 24,000 to 71,000psi as measured by ASTM D412. In still a further embodiment, the TPU composition has an elastic modulus of about 38,000psi at 23 ℃. The TPU composition typically has an elastic modulus at 130 ℃ of greater than 700, more typically greater than 1,200, and most typically greater than 2,500psi as measured by ASTM D412. In yet another further embodiment, the TPU composition has an elastic modulus of about 1,200% at 130 ℃. The TPU composition typically has a flexural modulus at 23 ℃ of greater than 40,000, more typically 40,000 to 150,000, and most typically 44,000 to 145,000psi as measured by ASTM D790. In still further embodiments, the TPU composition generally has a flexural modulus of about 80,000psi at 23 ℃. The TPU composition typically has a flexural modulus at 130 ℃ of greater than 2,000, more typically 2,000 to 20,000, and most typically 4,000 to 15,000psi as measured by ASTM D790. In still further embodiments, the TPU composition has an elastic modulus of about 10,000psi at 130 ℃.

In addition to the excellent high temperature properties as set forth above, the low temperature properties of the TPU composition are also excellent. The TPU composition has an Izod notched impact strength at-40 ℃ of greater than 0.5, or greater than 0.9, or greater than 2.0, or greater than 2.5 ft-lb/in as measured by ASTM D256-10 (method A). In various embodiments, most of the test specimens did not break when the TPU composition was tested for Izod notched impact strength at-40 ℃ according to ASTM D256-10 (method A). In other embodiments, all of the test specimens did not break when the TPU composition was tested for Izod notched impact strength at-40 ℃ according to ASTM D256-10 (method A).

In addition to the TPU composition, the present disclosure also provides a process for forming the TPU composition. The method of forming the TPU composition includes the step of combining the TPU, the polysiloxane and acetal polymer, and the ABS copolymer to form the TPU composition. The combining step may be performed by any method known in the art including, but not limited to, direct extrusion, ribbon extrusion, reactive injection molding, vertical mixing, horizontal mixing, feed mixing, and combinations thereof. In one embodiment, the combining step is further defined as feeding the TPU and acetal polymer to a compounding device, such as a single or twin screw extruder.

The process of forming the TPU composition can also include the step of heating the TPU and acetal polymer in the compounding device, outside the compounding device, or both. It will be appreciated that the TPU and acetal polymer are typically heated to a temperature of from 180 to 260, more typically from 180 to 220 ℃. It is believed that heating facilitates compounding of the TPU and acetal polymer. It is also contemplated that the process may include the step of tempering the TPU composition.

After the combining step, the process of forming the TPU composition can further include the step of pelletizing, dicing, or granulating the TPU composition. For example, the compounded TPU composition can be pelletized with an underwater pelletizer or a strand pelletizer.

In one embodiment, after the TPU composition is formed in the compounding device, the TPU composition is extruded on a twin screw extruder and pelletized, diced, or granulated upon discharge. In another embodiment, the TPU and acetal polymer are fed into a twin screw extruder and the TPU composition is extruded at a temperature less than or equal to about 210 ℃ to form a fluid transfer tube.

As noted above, the present disclosure also provides articles, such as fluid transfer tubes, formed from the TPU compositions. The term "fluid" is used herein to describe liquids, gases and plasmas. However, the article is not limited to fluid transfer tubes. That is, the article may be any article known in the art including, but not limited to, hose jackets, wire and cable jackets, wheel and caster tires, conveyor belts, mechanical articles, sporting articles, appliances and furniture, animal tags, golf balls, and compact disc covers.

Fluid transfer tubes containing the TPU compositions are durable and strong over a wide temperature range and are kink resistant. Kinking is measured using methods well known in the coil industry and art. This method employs a fluid transfer tube having an annular 8 mm diameter inner surface and an annular 12 mm diameter outer surface. In this method, the fluid transfer tube is coiled in an approximately circular shape with decreasing diameter until the fluid transfer tube kinks. This method defines kinking when 10% of the outer diameter of the fluid transport tube is flattened. At this point, the approximate circular diameter of the coil is recorded. The fluid transport tubes of the present disclosure generally remain kink-free when coiled to form an approximately circular shape having a diameter of 3 to 6 centimeters, more typically 4 to 5 centimeters, and most typically about 4 centimeters.

As noted above, the present disclosure also provides a method of forming the fluid transfer tube. The method of forming the fluid transfer tube includes the steps of combining the TPU and the polyoxymethylene to form a TPU composition and extruding the TPU composition to form the fluid transfer tube.

Of course, it is to be understood that the physical properties and dimensions mentioned above are not limiting and merely describe some embodiments of the present disclosure.

The present disclosure also provides a method of forming the fluid transfer tube. The method includes the step of extruding the TPU and acetal polymer to form a fluid transfer tube. The extrusion step may be further defined as extruding the TPU and acetal polymer simultaneously from a single extruder or from different extruders. Alternatively, the extrusion step may be further defined as extruding the TPU and acetal polymer at different times from the same extruder or from different extruders. The extruder is typically a single or twin screw extruder, but may be any extruder known in the art. The extrusion conditions may be any conditions known in the art.

The present invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Detailed Description

Examples

Thermoplastic polyurethane compositions 1-7(TPU compositions 1-7) are formed according to the present disclosure by compounding a Thermoplastic Polyurethane (TPU), polyoxymethylene, and a compatibilizer in a single screw extruder. The TPU composition is pelletized immediately after compounding/extrusion. Once pelletized, the TPU composition is injection molded into test panels using methods well known in the art. The test panels were analyzed to determine key physical/process performance properties of the TPU compositions. Comparative test panels formed from materials not conforming to the present disclosure were also analyzed and the results included for comparative purposes.

Referring now to Table 1, the amounts and types of the components used to form the TPU compositions 1-7 are indicated, wherein all values expressed in parts by weight are based on 100 parts by weight of the total TPU composition.

TABLE 1

TPU A is a polyester having a tensile strength of 40MPa at 23 ℃ as measured by ASTM D412, a Shore D hardness of 53pts as measured by ASTM D2240, and a hardness of 1.16g/cm³The specific gravity of (a) a polyether-based aromatic TPU.

TPU B is a polycarbonate having a tensile strength of 45MPa at 23 ℃ as measured by ASTM D412, a Shore D hardness of 73pts as measured by ASTM D2240, and 1.19g/cm³The specific gravity of (a) a polyether-based aromatic TPU.

The crosslinking agent is available from BASF Corporation

X-FLEX2905MB。

Polyoxymethylene is a polyolefin having a tensile modulus of 65MPa at 23 ℃ as measured by ASTM D412 and 1.4g/cm³High molecular weight polyoxymethylene.

The compatibilizer is a Low Density Polyethylene (LDPE) -based maleic anhydride grafted compatibilizer.

The TPU compositions 1-7 were compounded and extruded into strands in a single screw extruder. During extrusion, a single screw is rotated in a metal barrel at a speed (RPM) to compound and advance the TPU composition through the barrel. The barrel provides a bearing surface where shear forces are imparted to the TPU composition. The heating medium is packed around the barrel and creates a temperature zone in the barrel that varies according to processing conditions known to those skilled in the art. The process parameters used for compounding the TPU compositions 1-7 are set forth in Table 2 below. In the first zone (zone 1) the components are fed into a single screw extruder and passed through a series of additional zones (zones 2-6) which are heated to varying temperatures. The TPU composition is then advanced through a strand die to form a strand, which is cooled with water and pelletized. The TPU compositions 1-7, now in pellet form, were then molded into test panels using the injection molding process described below.

TABLE 2

Zone 1 temperature (. degree. C.)	210
		Zone 2 temperature (. degree. C.)	220
Zone 3 temperature (. degree. C.)	225
		Gate (. degree.C.)	225
Adapter (. degree.C.)	225
		Die temperature (. degree. C.)	225
Torque (psi)	800
		Pressure head (psi)	1100
Screw speed (RPM)	50
		Production rate (lb./hr.)	20
Melt temperature (. degree. C.)	240

The TPU compositions 1-7 and comparative compositions 1 and 2 were injection molded under the conditions described in table 3 below. Each test panel was approximately 5 "x 4" x 0.08 ".

TABLE 3

Comparative composition 1(CC1) was nylon 11.

Comparative composition 2(CC2) was nylon 12.

The test panels for TPU compositions 1-7 and comparative compositions 1 and 2 were tested over a range of temperatures to determine various physical and process performance properties. Once formed, the test panels were analyzed to determine various physical properties. The properties, test methods used and results are listed in table 4 below.

TABLE 4

As demonstrated by the results in table 4, the TPU compositions 1-7 of the present disclosure exhibit excellent physical properties over a wide temperature range. In view of the comparative compositions 1 and 2, these compositions can be used in applications that typically use other polymeric materials that are resistant to higher temperatures, such as nylon (polyamide), to achieve desired process performance properties.

It is to be understood that the appended claims are not limited to the specific and specific compounds, compositions, or methods described in the detailed description, as these may vary between specific embodiments within the scope of the appended claims. In regard to any markush group herein by which specific features or aspects of various embodiments are described, it is recognized that different, special and/or unexpected results can be obtained from each member of each markush group, independently of all other markush members. Each member of the markush group may be relied upon independently and/or in combination and provide adequate support for specific embodiments within the scope of the appended claims.

It is also to be understood that any ranges and subranges from which the various embodiments of the disclosure are described are independently and collectively within the scope of the appended claims, and are to be understood as describing and contemplating all ranges of integer and/or fractional values included therein, even if such values are not expressly written herein. Those skilled in the art will readily recognize that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present disclosure, and that such ranges and subranges can be further delineated into relevant 1/2, 1/3, 1/4, 1/5, and so forth. To name but one example, a range of "0.1 to 0.9" may be further delineated into lower 1/3, i.e., 0.1 to 0.3, middle 1/3, i.e., 0.4 to 0.6, and upper 1/3, i.e., 0.7 to 0.9, which are independently and collectively within the scope of the appended claims, may be depended upon independently and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. Further, to the extent that a range is defined or modified, such as "at least," "greater than," "less than," "not greater than," and the like, it is to be understood that such term includes subranges and/or an upper or lower limit. As another example, a range of "at least 10" inherently includes at least a subrange of 10 to 35, at least a subrange of 10 to 25, a subrange of 25 to 35, and so forth, and each subrange may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. Finally, independent numerical values within the disclosed ranges may be relied upon and provide sufficient support for specific embodiments within the scope of the appended claims. For example, a range of "1 to 9" includes various individual integers, such as 3, as well as individual values (or fractions) including decimal points, such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

Claims

1. A thermoplastic polyurethane composition comprising:

65 to 85 parts by weight of a thermoplastic polyurethane per 100 parts by weight of said thermoplastic polyurethane composition;

10 to 32 parts by weight of polyoxymethylene per 100 parts by weight of said thermoplastic polyurethane composition; and

a maleic anhydride-functional polyethylene or polypropylene-based compatibilizer; and

a crosslinking agent different from the maleic anhydride-functional polyethylene or polypropylene-based compatibilizer;

wherein the thermoplastic polyurethane composition has an Izod notched impact strength at-40 ℃ of greater than 0.5 ft-lb/in to 3.37 ft-lb/in as determined by ASTM D25610, method A, and an elastic modulus at 130 ℃ of greater than 700psi to 10,000psi as determined by ASTM D412;

wherein the thermoplastic polyurethane has a Shore D hardness of 51 to 75pts, as measured by ASTM D2240, and a specific gravity of 1.1 to 1.3g/cm³Wherein the thermoplastic polyurethane composition is selected from polyether-based thermoplastic polyurethanes.

2. A thermoplastic polyurethane composition as set forth in claim 1 wherein said thermoplastic polyurethane has a weight average molecular weight of greater than 50,000 g/mol.

3. A thermoplastic polyurethane composition as set forth in claim 1 wherein said thermoplastic polyurethane has a softening point of greater than 150 ℃ as measured by astm d 1525-09.

4. A thermoplastic polyurethane composition as set forth in claim 1 wherein said thermoplastic polyurethane has a tensile strength of from 2,000 to 10,000psi at 23 ℃ as measured by ASTM D412.

5. A thermoplastic polyurethane composition as set forth in claim 1 wherein said polyoxymethylene has a weight average molecular weight of greater than 50,000 g/mol.

6. A thermoplastic polyurethane composition as set forth in claim 1 wherein said polyoxymethylene has a melting point of greater than 160 ℃.

7. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 wherein said polyoxymethylene has a tensile strength of from 8,000 to 11,000psi at 23 ℃ as determined by ASTM D638.

8. A thermoplastic polyurethane composition as set forth in any one of claims 1-7 further comprising a crosslinking agent comprising a thermoplastic polyurethane carrier and an isocyanate component.

9. A thermoplastic polyurethane composition as set forth in claim 8 further comprising from 1 to 15 parts by weight of said crosslinking agent per 100 parts by weight of said thermoplastic polyurethane composition.

10. A thermoplastic polyurethane composition as set forth in any one of claims 1 to 6 having an Izod notched impact strength of greater than 0.9 ft-lb/in at-40 ℃ as determined by ASTM D25610, method A.

11. A thermoplastic polyurethane composition as set forth in any one of claims 1 to 6 having a tear strength of greater than 1,200pli at 23 ℃ as measured by ASTM D624, die C.

12. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 having a tensile strength of greater than 5000psi at 23 ℃ as measured by ASTM D412.

13. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 having a tensile strength of greater than 750psi at 130 ℃ as measured by ASTM D412.

14. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 having a flexural modulus as measured by ASTM D790 of greater than 40,000psi at 23 ℃ and greater than 2,000psi at 130 ℃.

15. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 having a Shore D hardness of from 50 to 100pts as measured by ASTM D2240.

16. A thermoplastic polyurethane composition as set forth in any one of claims 1-6 having from 1.11 to 1.25g/cm³Specific gravity of (a).

17. A fluid transfer tube formed from the thermoplastic polyurethane composition of any of claims 1-16.

18. A method of forming a fluid transfer tube as claimed in claim 17, the method comprising the steps of:

combining said thermoplastic polyurethane and said polyoxymethylene to form said thermoplastic polyurethane composition; and

extruding the thermoplastic polyurethane composition to form the fluid transfer tube.